On 02/21/2010 02:17 PM, w2xj wrote: > I have spent the last hour looking through part 97. I find nothing that > would prohibit ROS in the HF bands subject to adhering to those segments > where the bandwidth is allowed. In fact the rules would appear to > support such operation:
Lets look at it in another way. Part 97.3 is quite specific about what modes are considered spread spectrum: (8) SS. Spread-spectrum emissions using bandwidth-expansion modulation emissions having designators with A, C, D, F, G, H, J or R as the first symbol; X as the second symbol; X as the third symbol. ROS has no ITU designator marking it as spread spectrum. Furthermore, from part 97.307 places this limitation on any data mode transmitted in the HF bands: (2) No non-phone emission shall exceed the bandwidth of a communications quality phone emission of the same modulation type. The total bandwidth of an independent sideband emission (having B as the first symbol), or a multiplexed image and phone emission, shall not exceed that of a communications quality A3E emission. ROS follows this rule. In short, ROS has not been ruled to be a spread spectrum mode by the FCC or the ITU, and fits within the bandwidth of a phone communications signal on HF. It also follows the common sense rule of not causing any harm on the HF bands. It really is not much different from the other data modulations out there. JT65, Throb and RTTY also have empty space between carrier positions. I would certainly try out ROS, if it weren't for the fact that I don't have a Windows PC and ROS does not seem to run anywhere else... -- All rights reversed.